Composite explosive with a carboxylic polydiolefin binder

ABSTRACT

A composite explosive with a rubbery binder comprises particles of explosive material dispersed into a rubbery binder. The binder is a carboxylic polydiolefin based resin, the proportion of explosive material amounting to not more than 92 percent by weight of the composite explosive. To prepare the composite explosive, at least one carboxylic polydiolefin and at least one chain extending agent and/or reticulating agent are mixed with the particles of explosive substance. Said agent contains in each molecule at least two functional groups capable of reacting with the -COOH groups in the carboxylic polydiolefin. The resultant material is then poured. The reaction of the carboxylic polydiolefin and the said agent entrains the resin constituting the binder. The composite explosive according to the invention is used in applications requiring the use of homogeneous explosives of easy operation.

11' States Patent 1 1 Dubois De Prisque et al.

1451 Oct. 1,1974

Sevran; Andr Thibieroz, Miramas, all of France [73] Assignee: Societe Nationale Des Poudres Et Explosifs, Paris, France [22] Filed: Apr. 9, 1971 [21] Appl. No.: 132,873

[30] Foreign Application Priority Data Apr. 13, 1970 France 70.13194 [52] US. Cl l49/l9.9, 149/38, 149/44, 149/92 [51] Int. Cl C06b 15/02 [58] Field of Search 149/19, 38, 39, 40, 44, 149/76, 78, 83, 92, 93, 105

[56] References Cited UNITED STATES PATENTS 2,995,430 8/1961 Scharf 149/78 X 3,068,129 12/1962 Schaffel 149/93 X 3,166,451 1/1965 Young 149/39 3,338,764 8/1967 Evans 149/19 3,418,183 12/1968 Rice 149/19 X 3,418,184 12/1968 Vetter 149/19 3,419,445 12/1968 Markels 149/19 3,449,179 6/1969 Minekawa et al. 149/19 3,473,981 10/1969 Butts 149/92 X 3,476,622 11/1969 Harada et al. 149/19 3,646,174 2/1972 Marci 149/44 3,756,874 9/1973 Chang et a1 149/92 X Primary ExaminerLeland A. Sebastian Assistant Examiner-E. A. Miller [5 7 ABSTRACT A composite explosive with a rubbery binder comprises particles of explosive material dispersed into a rubbery binder. The binder is a carboxylic polydiolefin based resin, the proportion of explosive material amounting to not more than 92 percent by weight of the composite explosive. To prepare the composite explosive, at least one carboxylic polydiolefin and at least one chain extending agent and/or reticulating agent are mixed with the particles of explosive substance. Said agent contains in each molecule at least two functional groups capable of reacting with the -COOH groups in the carboxylic polydiolefin. The resultant material is then poured. The reaction of the carboxylic polydiolefin and the said agent entrains the resin constituting the binder. The composite explosive according to the invention is used in applications requiring the use of homogeneous explosives of easy operation.

11 Claims, No Drawing s W COMPOSITE EXPLOSIVE WITH A CARBOXYLIC POLYDIOLEFIN BINDER BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite explosive having a rubbery binder especially suited for manufacture by pouring. This invention also relates to its manufacturing process.

2. Prior Art The term composite explosive" is used to connote a mass of any shape having explosive properties and consisting essentially of a homogeneous dispersion of particles of some explosive substance in a possibly latticed binder which can also contain additives modifying the physical or detonatory characteristics.

For manufacturing composite explosive, the following processes are known:

a. Compression processes;

b. Extrusion processes;

c. Pouring processes.

The first two are the conventional processes; and they employ pressures which can be very high (2000 bars). In those processes the particles of explosive substance are imbedded in a binder and these particles are then subjected to high pressure at varying temperatures in order to obtain slabs (or cakes) having explosive properties. While the compression processes use high pressures, the extrusion processes make use of comparatively low pressure. The pouring processes operate without pressure.

The latest known pouring processes have the disadvantage of requiring a binder of precisely defined composition compatible with a delicate method of operation. This latter governs the quality of the end product.

Among the composite explosives with rubbery binders intended for manufacture by pouring, the following products are known to be usable:

l. Explosivecompositions comprising (by weight):

75 to 95% of explosive substance such as: cyclonite, trinitrotoluene, pentaerythritol tetranitrate, tetryl, nitroguanidine, picric acid, nitrolactose, mannitol octanitrate and saccharose octanitrate;

5 to 25% of a polysilicone binder.

There are two different ways to manufcature these compositions, namely: the explosive substance and a polymerizable silicone are mixed together and the resultant product is heated to a point below the decomposition temperature of the explosive substance, until a plastic composition is obtained; or

a polymerizable silicone is heated to form a gel having the required consistency, and the explosive substance is mixed into the polysilicone gel to produce the desired composition. These processes have the disadvantage of requiring reaction temperatures always higher than 100C and most frequently of the order of 125 to 150C which demand certain precautions in the manufacturing procedure. Also, the detonation rates obtained with such explosive compositions are lower than 7000 meters/see, and the polymerizable silicones used are not very cheap raw materials. Finally the pouring process employed does not allow the required precise shape and surface finish of the composite to be obtained.

2. Composite explosives in flexible sheets with a rubberized binder manufactured from an explosive material such as penthrite, hexogen, octogen, and an aqueous latex emulsion whose moisture is eliminated after pouring, during the molding process, by absorption in a mold or by drying. It is of course essential to completely eliminate that water with all the risks and difficulties that such an operation entails for the quality of the end product. Regardless of the method of operation used, whether absorption in a mold or drying, it is a delicate operation which in the case of drying is not inexpensive. This process most frequently requires machining of the surface in order to obtain the surface finish required, and this increases the cost still further and complicates the manufacture.

SUMMARY OF THE INVENTION The present invention aims at remedying, in a simple manner, the above noted drawbacks. It comprehends composite explosives of varied shaped with a binder composition perfectly defined and at the same time compatible to the explosive substance and the pouring method of operation.

The invention also provides a pouring process for manufacturing these varied forms of composite explosive with said binder composition.

The composite explosive comprises particles of an explosive substance dispersed into a binder which is a rubbery material. The explosive constitutes at most 92 percent by weight of the composite and may be a nitro explosive or an organic nitrate such as octogen, hexogen, penthrite, tetryl or tolite.

The binder is a resin based on at least one carboxylic polydiolefin. The composite may also include an oxidizer (up to 65 percent by weight of the total composite) such as a perchlorate. The composite may further include reducing metals, e.g., aluminum or magnesium; a plasticizer; an antioxidant and modifying adjuvants.

The composite is produced by mixing the explosive substance and the binder with a chain extending or reticulating agent at about 20 to 95C. to form a mass which is poured to the desired shape.

DETAILED DESCRIPTION According to the invention, the composite explosive comprising particles of explosive material dispersed into a binder made up of a rubbery material is characterized by the fact that the binder is a resin having at least one carboxylic polydiolefin base and the proportion of explosive material is at most 92 percent by weight of the total weight of the composite explosive.

The composite explosives produced according to the invention posses varied degrees of flexibility. The binder used is, in fact, a resin of which the composition and latticing rate are varied according to the required result, bearing in mind also the proportion of explosive material used.

The binder is preferably the reaction product of at least one carboxylic polydiolefin, that is, one containing COOH groups (at least two to each molecule) with at least one chain extending agent and/or reticulating agent.

The chain extending agent or reticulating agent contains for each molecule at least two functional groups capable of reacting with the COOH groups carried by the carboxylic polydiolefin which latter can, in these circumstances, be a prepolymer. The binder can also contain various secondary additives.

Certain preferred methods of working the invention will now be detailed.

In one advantageous embodiment, the binder is a carboxylic polybutadiene-based latticed resin. In this case, the resin making up the binder is the reaction product of at least one carboxylic polybutadiene comprising at least two COOH groups to each molecule, with at least one chain extending agent and/or reciculating agent, such agent containing in each molecule at least two functional groups capable of reacting with the COOH groups borne by the carboxylic polybutadiene.

The explosive substance is a very high explosive selected from among the nitro explosives and the organic nitrates, the proportion of explosive material advantageously being at least equal to 19 percent by weight of t the composite explosive.

As an explosive substance, there is some benefit in using very powerful high explosives according to the invention, and more particularly:

octogen homocyclonite or cyclotetramethylenetetranitramine, of the formula: (CH N N hexogen cyclonite or cyclotrimethylenetrinitramine:

(CH N 2):;

penthrite pentaerythritol tetranitrate:

tetryl 2,4,6-trinitrophenylmethylnitramine,

tolitc or trinitroltoluene,

3 ti 2( 2)1l' In another preferred embodiment of the invention, the explosive compound further contains a powerful oxidizer, the said oxidizer forming at most 65 percent by weight ofthe composite explosive. This powerful oxidizer can be a perchlorate such as potassium perchlorate or ammonium perchlorate. These perchlorates can be used either alone or mixed. The use of these oxidizers offers the advantage of effecting a significant saving.

The proportion of the binder according to the invention is greater than 8 percent by weight of the composite explosive and lies preferably between 8 and percent. It is thus possible to obtain extremely powerful composite high explosives.

The composite explosive advantageously contains a finely divided metal of very high reducing power, the said finely divided metal being intended to produce a luminous effect, a blasting effect or an incendiary action.

The finely divided metal is powdered aluminum or powdered magnesium.

The proportion of said finely divided metal of very high reducing power is at most 65 percent by weight of the composite explosive.

The binder composition according to the invention advantageously contains a plasticizer. The conventional polyolefin plasticizers such as:

waxes;

oils;

esters, such as dioctyl azelate;

liquid polybutadienes; and the like are used.

The proportion of the plasticizer is at most 60 percent by weight of the binder.

THe binder preferably contains an antioxidant. The conventional rubber antioxidants such as, for example: phenols and phosphites are used.

As a representative phosphite, Polygard (nonyl phenyl phosphate) can be mentioned.

As phenols, MBP'5, which is 2,2'-bismethylene (4- methyl-6-tertiobutylphenol), and IONOL, which is 2,6-di-tertisobutyl-p-cresol) can be mentioned.

The composite explosive according to the invention advantageously further contains adjuvants for modifying its physical and/or detonating properties (detonation velocity), for example minimum (Pb O,).

As to the process for manufacturing the composite explosive according to the invention, comprising particles of explosive material dispersed in a binder formed of rubbery material, the process comprises mixing at least one carboxylic polydiolefin and at least one chain extending agent and/or reticulating agent with the particles of explosive substance, the said agent containing, in each molecule, at least two functional groups capable of reacting with the COOH groups carried by the said carboxylic polydiolefin, and'pouring the resultant mass. The reaction of the carboxylic polydiolefin and the said agent induces the formation of the latticed resin which forms the binder.

The purpose of this process is to obtain directly, with the composition of the binder according to the invention, pieces of perfectly defined shape and in all sizes, having the desired surface finish and a density equal at all points to the theoretical density and not requiring subsequent machining.

We will now specify some of the preferred embodiments of the invention.

In one expedient method of operation, carboxylic polydiolefins whose molecular weights are in the range 1000 to 8000 and which contain between 0.2 and 3.0 gram-milliequivalents of -COOH are used. These carboxylic polydiolefins possess at least two COOH groups in each molecule and their viscosities are from to 800 poises at a temperature of 25C.

In the process according to the invention, the polydiolefin preferably possesses only two COOH groups per molecule attached to the ends of its main chain. A prepolymer of this kind, called carboxytelechelic, is used for obtaining products having the best elastic properties.

The chain extending agent and/or reticulating agent is selected from the group formed by the polyepoxides. These compounds contain substituted or nonsubstituted epoxy groups.

The characteristic feature of these epoxy groups is to open up by the addition of COOH groups without yielding light (small) molecules which have the tendency to consequently migrate or form gaseous occulsions within the composite explosive.

' distortion.

The mechanical characteristics of the binder lattice can be considerably changed by altering the molecular bulk of the carboxylic polydiolefm as well as the functional state of the said agent (number of epoxy groups per molecule) and its molecular mass.

The elasticity and pliancy of the binder lattice depends of course on the mean molecular weight of the chains bounded by the lattice nodes. The polydiolefins of high molecular weight, whose COOH groups are as far as possible from each other, have strong elasticity and a considerable ultimate elongation. If the best elastic and pliancy properties are required, it is advisable to use, according to one preferred embodiment of the invention, polydiolefins possessing only two COOH groups attached to the ends of the main chain. Such polydiolefins, known, as previously mentioned, as carboxytelechelic prepolymers are therefore those tending to yield products having the best elastic properties. Of course, as already indicated, the pliancy of the composite explosive depends not only on the properties of the binder but also on the amount of explosive substance. It is thus possible to get lumps and slabs of composite explosive having various degrees of pliancy.

The final properties of the rubbery lattice are determined by the latticing rate of the carboxylic polydiolefinbased resin. That rate can be changed by altering the relative proportions of bifunctional and multifunctional reticulating agents employed. The greater the mean number of reacting functional groups of the reticulating agent molecule, the closer the lattice and the stiffer the composite explosive obtained. Thus 0.8 to 1.3 epoxy groups is used for each COOH group. This figure represents the stoichiometric ratio of the epoxy groups of the polyepoxide relative to the COOH groups of the carboxylic polydiolefin. By changing the stoichiometric ratio around the value of unity, the latticing of the rubbery binder is altered and consequently its elasticity and pliancy characteristics.

According-to another method of employing the invention, the latticing is accelerated by means of catalyzers such as organometallic compounds like the acetylacetonates (tautomeric acetylacetone salts), alkylmetallic derivatives, resorcylic acid salts, salts of lauric acid, of Z-ethyl hexanoic acid, of a naphthenic acid (essentially alkylcyclopentanc-acetic acid), the metals being iron, lead, tin or cobalt.

In the process of the invention, a wetting agent is preferably incorporated, selected from following group of products:

waxes;

lanolin;

phosphatides, such as lecithin;

and certain substances such as sulfimel;

a-chloronaphthalene.

These products facilitate the kneading and pouring of the mixture.

Operation is preferably at temperatures between ambient termperature (about 20C. and C. To obtain a composite explosive of high loading strength, that is to say, containing a high proportion of explosive substance, it is advisable to knead the binder constituents under vacuum before introduction of the explosive. Since the operating temperatures are not particularly high, the explosive. substance is consequently mixed without any danger.

It is also possible to knead together in vacuum without any risk, the binder constituents and the explosive substance. The process according to the invention therefore represents an indisputable advantage over certain previous methods employing reaction temperatures fairly close to the decomposition point of the explosive substance. Thus, in the case of making composite explosives with polysilicone binder, the mixture is effected at temperatures which may reach C, entailing certain manufacturing difficulties (risks of explosion).

The mix can advantageously be oscillated during pouring or after pouring. This operation, which can be done under vacuum, is for degassing the paste.

According to one preferred embodiment of the invention, the baking of the product at the end of the process is effected at a temperature allowing hardening within a suitable time (temperature less than 95C).

The manufacturing process according to the invention therefore comprises in general the following operations:

l. Kneading the binder constituents under vacuum at a temperature always less than 95C.

2. Adding the explosive substance and kneading the whole mix together under vacuum at a temperature always lower than 95C. (These first two stages can be effected in one operation by: kneading the whole of the constituents of the binder and of the explosive substance together under vacuum at a temperature lower than 95 C).

3. Pouring the mix while oscillating it, preferably, under vacuum according to circumstances, in order to degas it. The mix can also be shaken after it has been poured.

4. Baking the mix at a temperature lower than 95C. The baking (hardening) time is several days.

This basic method of operation does not in any way limit the invention and variants of the process can be contemplated according to circumstances.

In particular, in slab manufacture, the vacuum degassing of the mix with oscillation is a very important stage of the process since it contributes greatly to preventing gaseous occlusions in the composite explosive and allows the desired surface finish to be obtained, which is an indisputable advantage over the prior arts of pouring with composite explosives with rubbery binder.

The purpose of the pouring process according to the invention is the direct procurement, with the binder composition made up of carboxylic polydiolefin-based resin, of pieces of perfectly defined shape and of all dimensions, having identical density at all points equal to 99.5 percent of the theoretical density as against the average 96 97 percent obtained by the former processes. These pieces do not split or fissure and they can be stuck directly onto the walls of the capacities into which they are poured, since they occupy the defined volume perfectly, whatever it may be, the polymerization contraction being negligible.

The composite explosives so obtained are very homogeneous and not very porous, contrary to those obtained by the compression processes. Their mechanical properties are similar to those of loaded rubber. They are not fragile. They possess excellent resilience and a very good aging behavior. Their surface finish after pouring is greatly superior to the results obtained by conventional pouring processes which most freqntly require costly machining operations in order to obtain the precise form and finish required. The composite explosives of this invention can reach very high detonation velocities.

The range of detonation velocities extends from 4000 to 8600 meters/sec.

The following table displays the detonation velocities in terms of the relative proportions of explosive substance (octogen) and binder.

Further details of the invention will appear from the following examples of composite explosives. These examples itemize the respective percentages by weight of the explosive substance and of the binder as well as the composition of such binder and the detonation velocity of the end product obtained.

The exact weight of the polyepoxide has to be ascertained before use, bearing the indicated stoichiometric ratio (in relation to the COOH groups of carboxylic polydiolefin) in mind.

For carboxylic polydiolefins, carboxytelechelic polybutadienes of molecular weights 2000 and 4000 are used in these examples.

As polyepoxides, use is made of:

liquid epoxy resins having 2.5 epoxy groups per kilogram;

Epon 812 which is a liquid epoxy resin having 6.5

epoxy groups per kilogram.

For this example, a kneader capable of working under vacuum. and the temperature of which can be adjusted between ambient temperature and 100C. is

used. In this machine kept at 90C all the binder constituents are introduced. The vacuum being obtained, the kneader is started so as to effect a degassing of the resultant mixture. The kneader is then stopped and the vacuum cut off. The explosive substance (octogen) is then added portion by portion, and after each addition the kneading proceeds under vacuum. Vacuum kneading is continued until the resultant stuff has a uniform consistency. The mixture is then run into a mold by means of a pouring device under vacuum with thermostat and oscillating arrangement. Pouring is effected at 90C, using the vacuum and oscillating arrangement.

Once the pouring is finished, the product is vacuum oscillated until degassing is complete. Perfect degassing is thus secured contributing largely to avoiding the presence of gas occlusions in the composite explosive lump. By this means the surface finish required is obtained. Finally the poured product is baked at the final kneading temperature; for this purpose the mold is placed in a zone kept at C.

EXAMPLE 2 The resulting product is very flexible.

EXAMPLE 3 explosive substance (penthritc) 75'71 binder Composition of Binder:

Carboxylic polybutadiene 4000 Epoxy resin (2.5 epoxy groups per kg) 1 stoichiometric ratio Dioctyl azelate Polygard Iron naphthenate Sulfimel a chloronaphthalene l s Detonation velocity of resultant explosive= EXAMPLE 4 Explosive substance (penthrite) binder Composition of Binder:

Carboxylic polybutadiene 4000 100 g Epon 812 (6.5 epoxy groups per kg) Stoichiometric 1 ratio Polygard l Z-ethylhexanoate of lead 1 Sulfimel l a chloronaphthalene l Detonation velocity of resultant explosive= UQOQOQOQ EXAMPLE 5 Explosive substance (penthrite) Ammonium perchlorate Binder Composition of Binder:

Carboxylic polybutadiene 4000 Epon 8 [2 (6.5 epoxy groups per kg) stoichiometric ratio 10 EXLMBMQEEEEQ Polygard l g Carboxylic polybutadiene 2000 lOO g Z-ethylhexanoate of lead I g Epon 8l2 (6.5 epoxy groups per kg) Stoichiometric l Sulfimel l g ratio a-chloronaphthalene l g 5 Dioctyl azelate 20 g Detonation velocity of resultant explosive= 4760 m/s. Iron naphthenate l g Voltalef wax l g a-chloronuphthulene l g Detonation velocity of resultant explosive= 8000 m/s.

EXAMPLE 6 Ex los've ub t c th 't 207 10 EXAMPLE 1 1 p l s sane pen He I Minium (Pb -,O 50% Binder 30% Composition of Binder: E

Carboxylic polybutadiene 4000 l g 35 3 1) ;z izfi xgs Epon 812 (6.5 epoxy groups per kg) Stoichiometric l Binder F l5 Composition of Binder:

P "l y j 10 g Carboxylic polybutadiene 2000 l00 g i of lead g Epon 812 (6.5 epoxy groups per kg) Stoichiometric l sulfimel I g D i t tyl azelate 0 g a-chloronaphthalene l g on napmhenme g Detonation velocity of resultant explosive= 4220 m/s. volmlef wax l g achloronaphthalene l g Detonation velocity of resultant explosive= 8350 m/s EXAMPLE 7 Explosive substance (penthrite) 20% EXAMPLE l2 Powdered aluminum 55% ggl fg of Binder Explosive substance (octogen) 75% Carlaoxylic polybutadiene 400 100 g g gg of Binder. Epon 812 (6.5 epoxy groups per kg) Stoichmmetnc l cu-rboxylic polyhumdiene 4000 100 g s x y melme 10 g Epon 812 (6.5 epoxy groups per kg) Stoichiometric l Polygard l g ggg I g gfize gg of lead g Z-ethylhexanoate of lead I g a-chloronaphthalene l g I a-chloronaphthalene l g Demnmonvelocm of resultant exploswe 4560 Detonation velocity of resultant explosive= 7200 m/s.

EXAMPLE 8 EXAMPLE 13 figzfig fi i Explosive substance (graphite-treated octogen) 8571 Binder 50% C W Composition of Binder: mpos tlon 9* 7 curhoxylic polybumdiene 4000 00 g Carhoxylie po lybutadlene E000 l00 g Epon 812 (6.5 epoxy groups per kg) Stoichiometric l Epoxy gmups per kg) 1 ratio Stoichiometrlc ratio Dioctyl azelute 10 g Dmcly date 20 g Polygard g Polygard 1 g Z-ethylhexanoate of lead l g naphhenute l g Sulfimel 1 g Sull'imel g mchlumnuphthulene I g Detonation velocity of resultant explosive= 8300 m/s. Detonation velocity of resultant explosive= 4560 m/s.

EXAMPLE 14 EXAMPLE 9 Explosive substance (penthrite) 20% Explosive substance (penthrite) 25% Minium a i) 35% Tolite 35% Binder 45% Binder 40% Composition of Binder:

Composition of Binder: Carboxylie polybutadiene 2000 100 g Carhoxylic polybutadiene 4000 100 g Epoxy resin (2.5 epoxy groups per kg) 1 Epon 812 (6.5 epoxy groups per kg) Stoichiometric l Stoichiometric ratio ratio Polygard 0.5 g Dioctyl azelate 10 g lron naththenate 1.0 g Polygard l g Sulfimel 0.5 g Z-ethylhexanoate of lead I g Detonation velocity of resultant explosive= 4050 m/s. Sullimel l g a-chloronaphthalene l g Detonation velocity of resultant explosivc= 6000 m/sv a The resulting lump IS very flexible.

The stuff becomes liquid after kneading. EXAMPLE l0 EXAMPLE l5 Explosive substance (oetogen) Explosive substance (penthrite) 60% Powdered aluminum l071 Binder 40% Binder l5% Composition of Binder:

Com osition of Binder: Carbox lic polybutadiene 4000 I00 g M LE lS-Continue I Epoxy resin (2.5 epoxy groups per kg) Stoichiometric ratio Ionol (2,6-di-tertisobutyl-p-cresol) 27 g Detonation velocity= 6500 m/s.

The resulting lump is very flexible.

EXAMPLE 17 Explosive substance (hexogen) 71% Powdered aluminum 7: Binder 1471 Binder composition:

Carhoxylic polyhutadiene 4000 1921 g Epoxy resin (25 epoxy groups per kg) 1.03 Stoichiometric ratio Dioctyl azelate 457 g Lead naphthenate 27 g lonol (2.6-di-tertisonutylp-cresol) 27 g Detonation velocity= 7750 m/s.

The resulting lump is very flexible.

In Examples 3-4 and 7-17 all the constituents are vacuum kneaded at 60C (both the binder and the explosive substance constituents).

In Example 6 all the constituents are also vacuum kneaded, but the work is done at a temperature of 45C.

In Example 2, the kneading is effected at 80C and first only the binder constituents are kneaded.

In Examples l-3, 7 and 13-17 the mix is vacuum poured.

In Examples 4-6 and 8-12, the mix is poured at atmospheric pressure.

In Examples 1-15 the mix is oscillated before being poured; after that vacuum degassing with oscillation is obtained and the product is finally baked while working at a temperature lower in every case than C.

In Examples 16 and 17, the mix is baked at 50C.

What is claimed is:

l. A cast, non-porous explosive article of detonation velocity between 4000 and 8600 meters/second, free from gas occlusions, comprising 19 92 percent by weight of an explosive which is a member selected from the group consisting of octogen, hexogen, pentrite, tetryl and tolite, dispersed in 8 20 percent by weight of a binder which is a rubbery material, said binder being the reaction product of at least one carboxylic polydiolefin, containing at least two carboxyl groups per molecule and a polyepoxy compound.

2. A composite explosive as claimed in claim 1, wherein the binder is a carboxylic polybutadiene-based resin.

3. A composite explosive as claimed in claim 1, further comprising an oxidizer, the said oxidizer constituting at most 65 percent by weight of the composite explosive.

4. A composite explosive as claimed in claim 3, wherein the oxidizer is a perchlorate.

5. A composite explosive as claimed in claim 4 wherein the perchlorate is potassium or ammonium perchlorate.

6. A composite explosive as claimed in claim 1, which comprises a finely divided metal which is powdered aluminum or powdered magnesium.

7. A composite explosive as claimed in claim 6, wherein the proportion of finely divided metal of extremely high reducing power is at most 65 percent by weight of the composite explosive.

8. A composite explosive as claimed in claim 1, further comprising a plasticizer.

9. A composite explosive as in claim 8, wherein the proportion of plasticizer is at most 60 percent by weight of the binder.

10. A composite explosive as claimed in claim 1, wherein the binder further comprises an antioxidant.

11. A composite explosive as claimed in claim 1, further comprising adjuvants for modifying the detonating properties of the explosive. 

1. A CAST, NON-POROUS EXPOLOSIVE ARTICLE OF DETONATION VELOCITY BETWEEN 4000 AND 8600 METERS/SECOND, FREE FROM GAS OCCLUSIONS, COMPRISING 19-92 PERCENT BU WEIGHT OF AN EXPLOSIVE WHICH IS A MEMBER SELECTED FROM THE GROUP CONSISTING OF OCTOGEN, HEXOGEN, PENTRITE, TETRYL AND TOLITE, DISPERSED IN 820 PERCENT BY WEIGHT OF A BINDER WHICH IS A RUBBERY MATERIAL, SAID BINDER BEING THE REACTION PRODUCT OF AT LEAST ONE CARBOXULIC POLYDIOLEFIN, CONTAINING AT LEAST TWO CARBOXYL GROUPS PER MOLECULE AND A POLYEPOXY COMPOUND.
 2. A composite explosive as claimed in claim 1, wherein the binder is a carboxylic polybutadiene-based resin.
 3. A composite explosive as claimed in claim 1, further comprising an oxidizer, the said oxidizer constituting at most 65 percent by weight of the composite explosive.
 4. A composite explosive as claimed in claim 3, wherein the oxidizer is a perchlorate.
 5. A composite explosive as claimed in claim 4 wherein the perchlorate is potassium or ammonium perchlorate.
 6. A composite explosive as claimed in claim 1, which comprises a finely divided metal which is powdered aluminum or powdered magnesium.
 7. A composite explosive as claimed in claim 6, wherein the proportion of finely divided metal of extremely high reducing power is at most 65 percent by weight of the composite explosive.
 8. A composite explosive as claimed in claim 1, further comprising a plasticizer.
 9. A composite explosive as in claim 8, wherein the proportion of plasticizer is at most 60 percent by weight of the binder.
 10. A composite explosive as claimed in claim 1, wherein the binder further comprises an antioxidant.
 11. A composite explosive as claimed in claim 1, further comprising adjuvants for modifying the detonating properties of the explosive. 